Exit on input 'exit'

 #include <stdio.h>
+#include <string.h>
 
 int main(void) {
 	printf("Input a string\n");
+	printf("Will exit on input \"exit\"\n");
 
 	while (1) {
 		char str[50];
 		scanf("%s", str);
-		printf("%s\n", str);
+		if (strcmp(str, "exit") == 0) {
+			break;
+		} else {
+			printf("%s\n", str);
+		}
 	}
 
 	return 0;